A comparative study on the different heat-treatment techniques applied to high manganese steel

Abstract

Hadfield manganese steel is the first choice by the mining and mineral processing industries because of its high work hardening rate, high wear resistance, ductility, and toughness properties. Sometimes Hadfield steel fails to give a better combination of these properties due to precipitation of the brittle carbides at the grain boundaries of austenite. Controlling of these (Fe, Mn)3C carbides provide high strength, ductility, toughness along with high work-hardening property and also a high wear and corrosion resistance to the steel. A suitable heat-treatment process helps to achieve carbide-free austenite grains, and it provides better mechanical properties. Hence, in the present investigation, a comparative analysis is carried out, which gives an idea about the different heat-treatment process parameters such as the heat-treatment sequence, temperature, heating rate, and cooling rate. A single-step or double-step heat-treatment process is applicable for the Hadfield steel. Recently it is reported that the double-step heat-treatment process is more efficient than the single-step heat-treatment. In the double-step heat-treatment process, initial heating up to 650 °C with a holding time of 3hrs and then heating up to 1100 °C with a holding time of 3hrs followed by water quenching dissolves the carbides for the Hadfield steel. To achieve a higher cooling rate in the heat-treatment process, water, salt solution, or a mixture of water and salt solution is used as the quenching media. From the present investigation, it is clear that a higher cooling rate, along with the double-step heat-treatment, gives a better combination of strength and ductility to Hadfield steel.